The present invention relates to an ink jet head, a method of manufacturing the same, and an ink jet recording apparatus.
In recent years, ink jet heads having densely arranged nozzles that are produced by using a so-called xe2x80x9ctransfer processxe2x80x9d are known in the art, as disclosed in, for example, Japanese Laid-Open Patent Publication No. 10-286953. A transfer process is an advantageous process as a method of producing a high-density print head. In a transfer process, first, a thin film actuator is produced as follows, for example. That is, a separate electrode is formed on a substrate made of single crystal MgO, or the like, and then a perovskite-type dielectric thin film made of PZT is formed as a piezoelectric member on the separate electrode. Moreover, a vibration plate that functions also as a common electrode is formed on the piezoelectric member by a method such as sputtering. Then, the thus produced actuator is attached to a pressure chamber plate, and the whole or part of the substrate is thereafter removed.
However, it was difficult to produce a line type ink jet head with the transfer process as described above for the following reasons.
In a line type ink jet head, the length of the ink jet head in the width direction (i.e., the longitudinal direction of the ink jet head) needs to be greater than the paper width of the recording paper. For example, in order to record information on A4-size paper, the length of the ink jet head in the width direction needs to be 210 mm or more. Therefore, the length of the single crystal MgO substrate in the longitudinal direction thereof also needs to be 210 mm or more. A single crystal MgO substrate is produced from a rock lump of MgO. However, the entire rock lump cannot be used, but what can actually be used is only a portion thereof. Therefore, in order to produce a single crystal MgO substrate whose length is 210 mm or more, it is necessary to provide a lump of MgO of such a length, thereby requiring very large equipment. Even if such a single crystal MgO substrate can be produced, it will be a very costly material because of a poor yield.
Moreover, in a transfer process, it is necessary to deposit, by sputtering, or the like, a piezoelectric element (e.g., PZT, etc.) on a substrate made of single crystal MgO, or the like. However, it requires very large equipment to deposit PZT over a large area. In addition, the yield lowers when one attempts to obtain a piezoelectric element film that is uniform in properties such as the piezoelectric property and the thickness and that has no crack therein. Therefore, the manufacturing cost becomes very high.
For the reasons as described above, it was difficult to use a transfer process for a conventional line type ink jet head in view of the quality and the cost.
An object of the present invention is to provide a high-density print head and a recording apparatus incorporating the same, with various advantages, including an improved uniformity of the thin film actuator in terms of properties such as the piezoelectric property and the thickness, prevention of a crack occurring in the film, improvement in the manufacturing yield, downsizing of the manufacturing equipment, a cost reduction, etc.
In the present invention, a plurality of actuator blocks including piezoelectric elements, etc., are provided for each pressure chamber plate, with the size of each actuator block being reduced.
A first ink jet head of the present invention is an ink jet head including: a plurality of actuator blocks each having at least a plurality of piezoelectric elements, and a first electrode and a second electrode for applying a voltage across each of the piezoelectric elements; and a pressure chamber block having therein a plurality of pressure chambers each containing an ink, the actuator blocks and the pressure chamber block being layered on each other, wherein: an area of a layering surface of each of the actuator blocks is smaller than an area of a layering surface of the pressure chamber block; and the plurality of actuator blocks are arranged on one surface of the pressure chamber block.
A second ink jet head is the first ink jet head, wherein the pressure chamber block includes: a pressure chamber plate having therein the plurality of pressure chambers each containing an ink; a channel plate having therein a plurality of ink channels respectively communicated to the pressure chambers and a common liquid chamber communicated to the pressure chambers; and a nozzle plate having therein a plurality of nozzles respectively communicated to the ink channels, the pressure chamber plate, the channel plate and the nozzle plate being layered on one another.
A third ink jet head is the first ink jet head, wherein the plurality of actuator blocks are arranged so that edge surfaces of ones of the actuator blocks adjacent to each other in a direction perpendicular to a scanning direction are not in contact with each other.
A fourth ink jet head is the first ink jet head, wherein the plurality of actuator blocks are arranged so as to be separated from one another so that adjacent ones of the actuator blocks partially overlap with each other with respect to a direction perpendicular to a scanning direction.
A fifth ink jet head is the first ink jet head, wherein the plurality of actuator blocks are arranged so that adjacent ones of the actuator blocks are spaced apart from each other in a scanning direction.
A sixth ink jet head is the first ink jet head, wherein the plurality of actuator blocks are arranged in a staggered pattern.
A seventh ink jet head is the first ink jet head, wherein the actuator blocks include, instead of the second electrode, a conductive vibration plate functioning also as the second electrode.
An eighth ink jet head is the second ink jet head, wherein: the nozzle plate is made of a single plate; and one or both of the pressure chamber plate and the channel plate includes alignment means for aligning the nozzle plate when the nozzle plate is layered on the channel plate.
Note that the alignment means includes various means such as, for example, an alignment hole or an optically-detected alignment marker.
A ninth ink jet head is the second ink jet head, wherein: the nozzle plate is made of a plurality of plates; and one or both of the pressure chamber plate and the channel plate includes alignment means for aligning the nozzle plates when the nozzle plates are layered on the channel plate.
A tenth ink jet head is the second ink jet head, wherein the ink jet head is obtained by producing an actuator block by sequentially layering at least the first electrode, the piezoelectric element, and the second electrode, on a substrate having a smaller area than that of the pressure chamber plate, and then transferring the actuator block onto the pressure chamber plate so that the plurality of pressure chambers provided in the pressure chamber plate are covered by the second electrode.
An eleventh ink jet head is the tenth ink jet head, wherein the substrate is an MgO single crystal substrate, and the piezoelectric element is produced by sputtering.
A twelfth ink jet head is the tenth ink jet head, wherein the substrate is an MgO single crystal substrate.
A thirteenth ink jet head is the tenth ink jet head, wherein the piezoelectric element is produced by sputtering.
A fourteenth ink jet head is the second ink jet head, wherein the ink jet head is obtained by producing an actuator block by sequentially layering at least the first electrode, the piezoelectric element, the second electrode, and a vibration plate, on a substrate having a smaller area than that of the pressure chamber plate, and then transferring the actuator block onto the pressure chamber plate so that the plurality of pressure chambers provided in the pressure chamberplate are covered by the vibration plate.
A fifteenth ink jet head is the fourteenth ink jet head, wherein the substrate is an MgO single crystal substrate, and the piezoelectric element is produced by sputtering.
A sixteenth ink jet head is the fourteenth ink jet head, wherein the substrate is an MgO single crystal substrate.
A seventeenth ink jet head is the fourteenth ink jet head, wherein the piezoelectric element is produced by sputtering.
An eighteenth ink jet head is an ink jet head including: a plurality of actuator blocks each having at least a plurality of piezoelectric elements, and a first electrode and a second electrode for applying a voltage across each of the piezoelectric elements; and a pressure chamber block having therein a plurality of pressure chambers respectively containing a plurality of types of ink, the actuator blocks and the pressure chamber block being layered on each other, wherein: an area of a layering surface of each of the actuator blocks is smaller than an area of a layering surface of the pressure chamber block; and the plurality of actuator blocks are arranged on one surface of the pressure chamber block.
A nineteenth ink jet head is the eighteenth ink jet head, wherein the pressure chamber block includes: a pressure chamber plate having therein a plurality of pressure chambers respectively containing a plurality of types of ink; a channel plate having therein a plurality of ink channels respectively communicated to the pressure chambers for the respective types of ink and a plurality of common liquid chambers respectively containing the types of ink and respectively communicated to the pressure chambers for the respective types of ink; and a nozzle plate having therein a plurality of nozzles respectively communicated to the ink channels for the respective types of ink, the pressure chamber plate, the channel plate and the nozzle plate being layered on one another.
A twentieth ink jet head is the nineteenth ink jet head, wherein the pressure chamber plate is made of a single plate.
A twenty-first ink jet head is the eighteenth ink jet head, wherein the plurality of types of ink include a black ink, a cyan ink, a magenta ink and a yellow ink.
A twenty-second ink jet head is the eighteenth ink jet head, wherein the plurality of actuator blocks are arranged so that edge surfaces of ones of the actuator blocks adjacent to each other in a direction perpendicular to a scanning direction are not in contact with each other.
A twenty-third ink jet head is the eighteenth ink jet head, wherein the plurality of actuator blocks are arranged so as to be separated from one another so that adjacent ones of the actuator blocks partially overlap with each other with respect to a direction perpendicular to a scanning direction.
A twenty-fourth ink jet head is the eighteenth ink jet head, wherein the plurality of actuator blocks are arranged so that adjacent ones of the actuator blocks are spaced apart from each other in a scanning direction.
A twenty-fifth ink jet head is the eighteenth ink jet head, wherein the plurality of actuator blocks are arranged in a staggered pattern.
A twenty-sixth ink jet head is an ink jet head including: a plurality of actuator blocks each having at least a plurality of piezoelectric elements, and a first electrode and a second electrode for applying a voltage across each of the piezoelectric elements; and a pressure chamber block having therein a plurality of pressure chambers respectively containing a plurality of types of ink, wherein the pressure chambers for the respective types of ink are successively arranged in a scanning direction, the actuator blocks and the pressure chamber block being layered on each other, wherein: an area of a layering surface of each of the actuator blocks is smaller than an area of a layering surface of the pressure chamber block; and the plurality of actuator blocks are arranged on one surface of the pressure chamber block so that each of the actuator blocks covers the pressure chambers for a plurality of types of ink.
A twenty-seventh ink jet head is the twenty-sixth ink jet head, wherein the pressure chamber block includes: a pressure chamber plate having therein a plurality of pressure chambers respectively containing a plurality of types of ink, wherein the pressure chambers for the respective types of ink are successively arranged in the scanning direction; a channel plate having therein a plurality of ink channels respectively communicated to the pressure chambers for the respective types of ink and a plurality of common liquid chambers respectively containing the types of ink and respectively communicated to the pressure chambers for the respective types of ink; and a nozzle plate having therein a plurality of nozzles respectively communicated to the ink channels for the respective types of ink, the pressure chamber plate, the channel plate and the nozzle plate being layered on one another.
A twenty-eighth ink jet head is the twenty-sixth ink jet head, wherein the plurality of types of ink include a black ink, a cyan ink, a magenta ink and a yellow ink.
A twenty-ninth ink jet head is the twenty-sixth ink jet head, wherein the plurality of actuator blocks are arranged so that edge surfaces of ones of the actuator blocks adjacent to each other in a direction perpendicular to a scanning direction are not in contact with each other.
A thirtieth ink jet head is the twenty-sixth ink jet head, wherein the plurality of actuator blocks are arranged so as to be separated from one another so that adjacent ones of the actuator blocks partially overlap with each other with respect to a direction perpendicular to the scanning direction.
A thirty-first ink jet head is the twenty-sixth ink jet head, wherein the plurality of actuator blocks are arranged so that adjacent ones of the actuator blocks are spaced apart from each other in a scanning direction.
A thirty-second ink jet head is the twenty-sixth ink jet head, wherein the plurality of actuator blocks are arranged in a staggered pattern.
A thirty-third ink jet head is an ink jet head including: a plurality of actuator blocks each having at least a plurality of piezoelectric elements, and a first electrode and a second electrode for applying a voltage across each of the piezoelectric elements; and a pressure chamber block having therein a plurality of pressure chambers each containing an ink, a plurality of nozzles, a plurality of ink channels for guiding the ink in the pressure chambers to the nozzles, respectively, and a common liquid chamber communicated to the plurality of pressure chambers, the actuator blocks and the pressure chamber block being layered on each other, wherein: an area of a layering surface of each of the actuator blocks is smaller than an area of a layering surface of the pressure chamber block; and the plurality of actuator blocks are arranged on one surface of the pressure chamber block.
A first ink jet recording apparatus of the present invention is an ink jet recording apparatus for recording information using a plurality of colors of ink, including: a plurality of the first ink jet heads independently provided for the respective colors of ink; and movement means for relatively moving the ink jet heads and a recording medium with respect to each other in a scanning direction.
A second ink jet recording apparatus is an ink jet recording apparatus including: the eighteenth ink jet head; and movement means for relatively moving the ink jet head and a recording medium with respect to each other in a scanning direction.
A third ink jet recording apparatus is an ink jet recording apparatus including: the twenty-sixth ink jet head; and movement means for relatively moving the ink jet head and a recording medium with respect to each other in a scanning direction.
A first manufacturing method of the present invention is a method including: a block production step of producing a plurality of actuator blocks by sequentially layering at least a first electrode, a piezoelectric element, and a second electrode, or by sequentially layering at least a first electrode, a piezoelectric element, a second electrode, and a vibration plate, on each of a plurality of substrates each having a smaller area than that of a pressure chamber plate; a first attachment step of attaching the actuator blocks layered on the respective substrates to one surface of the pressure chamber plate so that some of a plurality of pressure chambers provided in the pressure chamber plate are covered by the second electrode or the vibration plate of each of the actuator blocks; a step of removing the substrates; and a step of patterning the first electrode of each of the actuator blocks.
A second manufacturing method is the first manufacturing method including, after the step of patterning the first electrode: a step of attaching a channel plate on the other surface of the pressure chamber plate, the channel plate having therein ink channels for guiding the ink in the pressure chambers to nozzles, respectively, and a common liquid chamber; and a step of attaching a nozzle plate having therein the nozzles to the channel plate.
A third manufacturing method is the first manufacturing method, wherein the first attachment step is a step of attaching the plurality of actuator blocks to be separated from one another so that adjacent ones of the actuator blocks partially overlap with each other with respect to a direction perpendicular to the scanning direction.
A fourth manufacturing method is the first manufacturing method, wherein the first attachment step is a step of arranging the plurality of actuator blocks in a staggered pattern.
A fifth manufacturing method is the first manufacturing method, wherein the substrate is an MgO single crystal substrate.
A sixth manufacturing method is the first manufacturing method, wherein the block production step includes a step of producing the piezoelectric element by sputtering.
A seventh manufacturing method is the first manufacturing method, wherein the block production step includes a step of layering a conductive vibration plate functioning also as the second electrode, instead of layering the second electrode.
A fourth ink jet recording apparatus is an ink jet recording apparatus including: an ink jet head produced by the first manufacturing method; and movement means for relatively moving the ink jet head and a recording medium with respect to each other in a scanning direction.
An eighth manufacturing method is a method including: a block production step of producing a plurality of actuator blocks by sequentially layering at least a first electrode, a piezoelectric element, and a second electrode, or by sequentially layering at least a first electrode, a piezoelectric element, a second electrode, and a vibration plate, on each of a plurality of substrates each having a smaller area than that of a pressure chamber plate; a first attachment step of attaching the actuator blocks layered on the respective substrates to one surface of the pressure chamber plate so that some of a plurality of pressure chambers provided in the pressure chamber plate are covered by the second electrode or the vibration plate of each of the actuator blocks; a step of removing the substrates; a step of patterning the first electrode of each of the actuator blocks; and a step of patterning the piezoelectric element of each of the actuator blocks.
A ninth manufacturing method is the eighth manufacturing method including, after the step of patterning the piezoelectric element: a step of attaching a channel plate on the other surface of the pressure chamber plate, the channel plate having therein ink channels for guiding the ink in the pressure chambers to nozzles, respectively, and a common liquid chamber; and a step of attaching a nozzle plate having therein the nozzles to the channel plate.
A tenth manufacturing method is the eighth manufacturing method, wherein the first attachment step is a step of attaching the plurality of actuator blocks to be separated from one another so that adjacent ones of the actuator blocks partially overlap with each other with respect to a direction perpendicular to the scanning direction.
An eleventh manufacturing method is the eighth manufacturing method, wherein the first attachment step is a step of arranging the plurality of actuator blocks in a staggered pattern.
A twelfth manufacturing method is the eighth manufacturing method, wherein the substrate is an MgO single crystal substrate.
A thirteenth manufacturing method is the eighth manufacturing method, wherein the block production step includes a step of producing the piezoelectric element by sputtering.
A fourteenth manufacturing method is the eighth manufacturing method, wherein the block production step includes a step of layering a conductive vibration plate functioning also as the second electrode, instead of layering the second electrode.
A fifth ink jet recording apparatus is an ink jet recording apparatus including: an ink jet head produced by the eighth manufacturing method; and movement means for relatively moving the ink jet head and a recording medium with respect to each other in a scanning direction.
With the first, eighteenth and thirty-third ink jet heads, and the first and second ink jet recording apparatuses, a plurality of actuator blocks are provided for each pressure chamber block, whereby the size of each actuator block is reduced. Therefore, even when producing a line type ink jet head, it is not necessary to form an actuator block to such a large size substantially equal to the head width. Therefore, there are provided various advantages, including an improved uniformity of the thin film actuator in terms of properties such as the piezoelectric property and the thickness, prevention of a crack occurring in the film, improvement in the manufacturing yield, downsizing of the manufacturing equipment, a cost reduction, etc.
With the second, nineteenth and twenty-seventh ink jet heads, the pressure chamber block can be provided with a simple structure.
With the third, twenty-second and twenty-ninth ink jet heads, actuator blocks adjacent to each other in the direction perpendicular to the scanning direction do not overlap with each other, thereby improving the reliability of the actuators on the pressure chambers located near the edges of the actuator blocks.
With the fourth, twenty-third and thirtieth ink jet heads, and the third and tenth manufacturing methods, since the actuator blocks are arranged so that adjacent actuator blocks partially overlap with each other with respect to the direction perpendicular to the scanning direction (i.e., the head width direction), all the pressure chambers arrayed in the head width direction will be reliably covered by the actuator blocks. Therefore, despite a plurality of actuator blocks are used, the production error and the positioning error thereof can be tolerated to a considerable extent, thereby improving the yield.
With the fifth, twenty-fourth and thirty-first ink jet heads, adjacent actuator blocks are spaced apart from each other in the scanning direction, whereby the actuator blocks will not physically overlap with each other even if the positional precision of the actuator blocks is somewhat low or if the error in the shape of the actuator blocks is somewhat large.
With the sixth, twenty-fifth and thirty-second ink jet heads, and the fourth and eleventh manufacturing methods, the length of the ink jet head in the scanning direction (i.e., the direction perpendicular to the head width direction) decreases.
With the seventh ink jet head, and the seventh and fourteenth manufacturing methods, the number of components is reduced.
With the eighth and ninth ink jet heads, the nozzles are precisely aligned, thereby improving the quality of the ink jet head. Moreover, the yield is also improved.
With the ninth ink jet head, the nozzle plate is used only where it is needed, thereby reducing the cost. Moreover, the number of nozzles to be processed for each nozzle plate is reduced, thereby improving the yield.
With the tenth and fourteenth ink jet heads, effects as those obtained for the first ink jet head can be obtained for an ink jet head that is produced by a transfer process.
With the eleventh, twelfth, thirteenth, fifteenth, sixteenth and seventeenth ink jet heads, and the fifth, sixth, twelfth and thirteenth manufacturing methods, a piezoelectric element having a desirable piezoelectric property can be obtained.
With the twentieth ink jet head, the alignment of the various components can be done with respect to a single pressure chamber plate as a reference, whereby the ink jet head can be produced with a high precision.
With the twenty-first and twenty-eighth ink jet heads, at least four colors of ink are used, and a color image is obtained.
With the twenty-sixth ink jet head, and the third ink jet recording apparatus, each actuator block covers pressure chambers for a plurality of types of ink, whereby the number of actuators included in one actuator block is increased. Therefore, the density of the pressure chambers and the actuators increases. As a result, the ink jet head is downsized and the material cost is reduced.
With the first and second manufacturing methods, and the fourth ink jet recording apparatus, there are provided various advantages, including an improved uniformity of the thin film actuator in terms of properties such as the piezoelectric property and the thickness, prevention of a crack occurring in the film, improvement in the manufacturing yield, downsizing of the manufacturing equipment, a cost reduction, etc.
With the eighth and ninth manufacturing methods, and the fifth ink jet recording apparatus, not only the first electrode but also the piezoelectric element is patterned, whereby the actuator becomes more flexible. Accordingly, the voltage required for causing a predetermined flexural deformation in the actuator can be reduced. Therefore, it is possible to produce a power-conservative ink jet head.
As described above, according to the present invention, an actuator is formed by a plurality of actuator blocks, and the plurality of actuator blocks are provided for a pressure chamber plate, whereby the size of each actuator block can be reduced. Therefore, there are provided various advantages, including an improved uniformity of the thin film actuator in terms of properties such as the piezoelectric property and the thickness, prevention of a crack occurring in the film, improvement in the manufacturing yield, downsizing of the manufacturing equipment, a cost reduction, etc.
Moreover, since the plurality of actuator blocks are arranged so that they do not contact one another but partially overlap with one another with respect to the head width direction, the production error and the arrangement error of the actuator blocks can be tolerated to a considerable extent, thereby further improving the yield.